The Aggressive House Spider

Tegenaria agrestis

This common funnel-weaving spider is found in. Its body is about l/2 inch long; it has a dull tan color with darker markings on its oval abdomen. This spider makes thick webs with the funnel neck back in a wall crevice and the wider mouth opening into a room.

They are found only in moist areas of basements or cellars, in ground level window wells, and so forth. The spider has been given its name because it readily bites when touched or pressed. The bite, not initially painful, resembles the bite of the Brown Recluse spider and other bites that result in ulcerating lesions. These cellar-dwelling, funnel-weaving spiders were introduced from Europe where they are very commonly found in structures.

Cobweb Spiders

Cobweb weaving spiders make small irregular webs. These webs are characteristically found indoors in the upper inside corners of window frames. There are many species of cobweb spiders and the Black Widow is one of them. Most all of them are smaller than the Black Widow. They have the same type of globular abdomen, but it is always dull in color and not as eye catching. These quiet spiders hang in the web and wait for small insects to blunder onto their snares.

The problem with cobweb spiders inside buildings is that when they feed, they defecate drops of feces that dry and discolor anything they fall on. These spots are difficult to remove from painted wooden trim. Regular dusting eliminates cobweb spider problems. In historically significant buildings and museums their presence should be called to the attention of building supervisors.